Hp firebird 802 overclocking settings and general hardware optimizing

i just got an hp firebird 802 and was wondering what the best settings would be to oc the cpu? also i know that most of these subsequent questions are not about overclocking but i would also like these answered if possible. and fyi i took it out of box but havent started it once yet let alone plugged it in. so overall, these are the questions i pose:

1) what settings should i set in the bios to oc the cpu to the most optimal level?

2) how would i go about permantly oc'ing the graphics cards? and what would the be the optimal way to do this and settings that go along with it.

3) as the firebird 802 has an external 350 watt power supply would oc'ing the hardware cause power problems?

4) if i replace the ddr2 2gb sticks with 4gb sticks which should i go with and would there be compatibility issues?

5) same question as #1 but for the memory.

6) out of the two hard drives, which is the master, as i would like to replace the secondary hdd, also i can't find specs on the mb cache on the hdds. so i would like to match the rpm and mb cache of the master hdd but enlarge the storage capacity. i dont know about compatibilty issues though i.e. different rpms for hdds and different caches.

7) i would like to get an external blu-ray reader writer combo, what do you suggest for the best possible one i can get that has reliable up-to-date firmware, and reliable firmware updates. also i dont know if compatibilty would be an issue but if so please let me know. since its external i wouldnt think so.

thank you all very much for your answers. my current pc was built by myself so i am somewhat mod capable. i built it 5 years ago so im not too current on new configurations but like i said it has been 5 years and it hasnt broken on me so i must have done something right when i built it and again i already have the hp firebird 802 so i am committed to making this thing as good as i can. thank you.